Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Neuropathol Appl Neurobiol ; 49(2): e12894, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36843390

RESUMEN

AIMS: Glioneuronal tumours (GNTs) are poorly distinguished by their histology and lack robust diagnostic indicators. Previously, we showed that common GNTs comprise two molecularly distinct groups, correlating poorly with histology. To refine diagnosis, we constructed a methylation-based model for GNT classification, subsequently evaluating standards for molecular stratification by methylation, histology and radiology. METHODS: We comprehensively analysed methylation, radiology and histology for 83 GNT samples: a training cohort of 49, previously classified into molecularly defined groups by genomic profiles, plus a validation cohort of 34. We identified histological and radiological correlates to molecular classification and constructed a methylation-based support vector machine (SVM) model for prediction. Subsequently, we contrasted methylation, radiological and histological classifications in validation GNTs. RESULTS: By methylation clustering, all training and 23/34 validation GNTs segregated into two groups, the remaining 11 clustering alongside control cortex. Histological review identified prominent astrocytic/oligodendrocyte-like components, dysplastic neurons and a specific glioneuronal element as discriminators between groups. However, these were present in only a subset of tumours. Radiological review identified location, margin definition, enhancement and T2 FLAIR-rim sign as discriminators. When validation GNTs were classified by SVM, 22/23 classified correctly, comparing favourably against histology and radiology that resolved 17/22 and 15/21, respectively, where data were available for comparison. CONCLUSIONS: Diagnostic criteria inadequately reflect glioneuronal tumour biology, leaving a proportion unresolvable. In the largest cohort of molecularly defined glioneuronal tumours, we develop molecular, histological and radiological approaches for biologically meaningful classification and demonstrate almost all cases are resolvable, emphasising the importance of an integrated diagnostic approach.


Asunto(s)
Neoplasias Encefálicas , Neoplasias del Sistema Nervioso Central , Neoplasias Neuroepiteliales , Radiología , Humanos , Neoplasias Encefálicas/patología , Metilación de ADN , Neoplasias Neuroepiteliales/genética , Neoplasias del Sistema Nervioso Central/genética
3.
Neuropathol Appl Neurobiol ; 47(6): 781-795, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33797808

RESUMEN

AIMS: We understand little of the pathogenesis of developmental cortical lesions, because we understand little of the diversity of the cell types that contribute to the diseases or how those cells interact. We tested the hypothesis that cellular diversity and cell-cell interactions play an important role in these disorders by investigating the signalling molecules in the commonest cortical malformations that lead to childhood epilepsy, focal cortical dysplasia (FCD) and tuberous sclerosis (TS). METHODS: Transcriptional profiling clustered cases into molecularly distinct groups. Using gene expression data, we identified the secretory signalling molecules in FCD/TS and characterised the cell types expressing these molecules. We developed a functional model using organotypic cultures. RESULTS: We identified 113 up-regulated secretory molecules in FCDIIB/TS. The top 12 differentially expressed genes (DEGs) were validated by immunohistochemistry. This highlighted two molecules, Chitinase 3-like protein 1 (CHI3L1) and C-C motif chemokine ligand 2 (CCL2) (MCP1) that were expressed in a unique population of small cells in close proximity to balloon cells (BC). We then characterised these cells and developed a functional model in organotypic slice cultures. We found that the number of CHI3L1 and CCL2 expressing cells decreased following inhibition of mTOR, the main aberrant signalling pathway in TS and FCD. CONCLUSIONS: Our findings highlight previously uncharacterised small cell populations in FCD and TS which express specific signalling molecules. These findings indicate a new level of diversity and cellular interactions in cortical malformations and provide a generalisable approach to understanding cell-cell interactions and cellular heterogeneity in developmental neuropathology.


Asunto(s)
Encéfalo/metabolismo , Discapacidades del Desarrollo/metabolismo , Malformaciones del Desarrollo Cortical/patología , Transducción de Señal/fisiología , Esclerosis Tuberosa/metabolismo , Encéfalo/patología , Discapacidades del Desarrollo/patología , Humanos , Inmunohistoquímica , Malformaciones del Desarrollo Cortical/metabolismo , Malformaciones del Desarrollo Cortical de Grupo I/metabolismo , Esclerosis Tuberosa/genética , Esclerosis Tuberosa/patología
4.
J Pathol ; 250(5): 510-517, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32057098

RESUMEN

Brain tumours are the most common tumour-related cause of death in young people. Survivors are at risk of significant disability, at least in part related to the effects of treatment. Therefore, there is a need for a precise diagnosis that stratifies patients for the most suitable treatment, matched to the underlying biology of their tumour. Although traditional histopathology has been accurate in predicting treatment responses in many cases, molecular profiling has revealed a remarkable, previously unappreciated, level of biological complexity in the classification of these tumours. Among different molecular technologies, DNA methylation profiling has had the most pronounced impact on brain tumour classification. Furthermore, using machine learning-based algorithms, DNA methylation profiling is changing diagnostic practice. This can be regarded as an exemplar for how molecular pathology can influence diagnostic practice and illustrates some of the unanticipated benefits and risks. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Asunto(s)
Neoplasias del Sistema Nervioso Central/diagnóstico , Neoplasias del Sistema Nervioso Central/genética , Metilación de ADN/genética , Regulación Neoplásica de la Expresión Génica/genética , Patología Molecular , Algoritmos , Biomarcadores de Tumor/genética , Neoplasias del Sistema Nervioso Central/patología , Humanos , Patología Molecular/métodos
5.
Acta Neuropathol ; 135(1): 115-129, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29058119

RESUMEN

Glioneuronal tumours are an important cause of treatment-resistant epilepsy. Subtypes of tumour are often poorly discriminated by histological features and may be difficult to diagnose due to a lack of robust diagnostic tools. This is illustrated by marked variability in the reported frequencies across different epilepsy surgical series. To address this, we used DNA methylation arrays and RNA sequencing to assay the methylation and expression profiles within a large cohort of glioneuronal tumours. By adopting a class discovery approach, we were able to identify two distinct groups of glioneuronal tumour, which only partially corresponded to the existing histological classification. Furthermore, by additional molecular analyses, we were able to identify pathogenic mutations in BRAF and FGFR1, specific to each group, in a high proportion of cases. Finally, by interrogating our expression data, we were able to show that each molecular group possessed expression phenotypes suggesting different cellular differentiation: astrocytic in one group and oligodendroglial in the second. Informed by this, we were able to identify CCND1, CSPG4, and PDGFRA as immunohistochemical targets which could distinguish between molecular groups. Our data suggest that the current histological classification of glioneuronal tumours does not adequately represent their underlying biology. Instead, we show that there are two molecular groups within glioneuronal tumours. The first of these displays astrocytic differentiation and is driven by BRAF mutations, while the second displays oligodendroglial differentiation and is driven by FGFR1 mutations.


Asunto(s)
Neoplasias Encefálicas/metabolismo , Epilepsia/metabolismo , Ganglioglioma/metabolismo , Neoplasias Neuroepiteliales/metabolismo , Adolescente , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Niño , Preescolar , Estudios de Cohortes , Metilación de ADN , Epilepsia/genética , Epilepsia/patología , Epilepsia/cirugía , Femenino , Ganglioglioma/genética , Ganglioglioma/patología , Ganglioglioma/cirugía , Expresión Génica , Humanos , Lactante , Masculino , Mutación , Neoplasias Neuroepiteliales/genética , Neoplasias Neuroepiteliales/patología , Neoplasias Neuroepiteliales/cirugía , Fenotipo , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas B-raf/metabolismo , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/metabolismo
6.
Acta Neuropathol ; 135(5): 757-777, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29541918

RESUMEN

Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. ß-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.


Asunto(s)
Craneofaringioma/metabolismo , Sistema de Señalización de MAP Quinasas , Neoplasias Hipofisarias/metabolismo , Transcriptoma , Microambiente Tumoral/fisiología , Animales , Biología Computacional , Craneofaringioma/patología , Craneofaringioma/terapia , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Inflamación/metabolismo , Inflamación/terapia , Captura por Microdisección con Láser , Ratones , Neuroglía/metabolismo , Odontogénesis/fisiología , Hipófisis/embriología , Hipófisis/patología , Neoplasias Hipofisarias/patología , Neoplasias Hipofisarias/terapia , Análisis de Secuencia de ARN , Técnicas de Cultivo de Tejidos
7.
Lancet Oncol ; 18(7): 958-971, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28545823

RESUMEN

BACKGROUND: International consensus recognises four medulloblastoma molecular subgroups: WNT (MBWNT), SHH (MBSHH), group 3 (MBGrp3), and group 4 (MBGrp4), each defined by their characteristic genome-wide transcriptomic and DNA methylomic profiles. These subgroups have distinct clinicopathological and molecular features, and underpin current disease subclassification and initial subgroup-directed therapies that are underway in clinical trials. However, substantial biological heterogeneity and differences in survival are apparent within each subgroup, which remain to be resolved. We aimed to investigate whether additional molecular subgroups exist within childhood medulloblastoma and whether these could be used to improve disease subclassification and prognosis predictions. METHODS: In this retrospective cohort study, we assessed 428 primary medulloblastoma samples collected from UK Children's Cancer and Leukaemia Group (CCLG) treatment centres (UK), collaborating European institutions, and the UKCCSG-SIOP-PNET3 European clinical trial. An independent validation cohort (n=276) of archival tumour samples was also analysed. We analysed samples from patients with childhood medulloblastoma who were aged 0-16 years at diagnosis, and had central review of pathology and comprehensive clinical data. We did comprehensive molecular profiling, including DNA methylation microarray analysis, and did unsupervised class discovery of test and validation cohorts to identify consensus primary molecular subgroups and characterise their clinical and biological significance. We modelled survival of patients aged 3-16 years in patients (n=215) who had craniospinal irradiation and had been treated with a curative intent. FINDINGS: Seven robust and reproducible primary molecular subgroups of childhood medulloblastoma were identified. MBWNT remained unchanged and each remaining consensus subgroup was split in two. MBSHH was split into age-dependent subgroups corresponding to infant (<4·3 years; MBSHH-Infant; n=65) and childhood patients (≥4·3 years; MBSHH-Child; n=38). MBGrp3 and MBGrp4 were each split into high-risk (MBGrp3-HR [n=65] and MBGrp4-HR [n=85]) and low-risk (MBGrp3-LR [n=50] and MBGrp4-LR [n=73]) subgroups. These biological subgroups were validated in the independent cohort. We identified features of the seven subgroups that were predictive of outcome. Cross-validated subgroup-dependent survival models, incorporating these novel subgroups along with secondary clinicopathological and molecular features and established disease risk-factors, outperformed existing disease risk-stratification schemes. These subgroup-dependent models stratified patients into four clinical risk groups for 5-year progression-free survival: favourable risk (54 [25%] of 215 patients; 91% survival [95% CI 82-100]); standard risk (50 [23%] patients; 81% survival [70-94]); high-risk (82 [38%] patients; 42% survival [31-56]); and very high-risk (29 [13%] patients; 28% survival [14-56]). INTERPRETATION: The discovery of seven novel, clinically significant subgroups improves disease risk-stratification and could inform treatment decisions. These data provide a new foundation for future research and clinical investigations. FUNDING: Cancer Research UK, The Tom Grahame Trust, Star for Harris, Action Medical Research, SPARKS, The JGW Patterson Foundation, The INSTINCT network (co-funded by The Brain Tumour Charity, Great Ormond Street Children's Charity, and Children with Cancer UK).


Asunto(s)
Neoplasias Cerebelosas/clasificación , Neoplasias Cerebelosas/genética , Metilación de ADN , Meduloblastoma/clasificación , Meduloblastoma/genética , Transcriptoma , Adolescente , Factores de Edad , Neoplasias Cerebelosas/patología , Neoplasias Cerebelosas/radioterapia , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Amplificación de Genes , Humanos , Lactante , Recién Nacido , Factores de Transcripción de Tipo Kruppel/genética , Masculino , Meduloblastoma/patología , Meduloblastoma/radioterapia , Mutación , Proteína Proto-Oncogénica N-Myc/genética , Proteínas Nucleares/genética , Receptor Patched-1/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Represoras/genética , Estudios Retrospectivos , Medición de Riesgo/métodos , Factores de Riesgo , Receptor Smoothened/genética , Tasa de Supervivencia , Telomerasa/genética , Proteína p53 Supresora de Tumor/genética , Proteína Gli2 con Dedos de Zinc , beta Catenina/genética
8.
Curr Opin Ophthalmol ; 27(3): 210-6, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26913740

RESUMEN

PURPOSE OF REVIEW: Diabetic retinopathy and diabetic macular edema (DME) are common eye diseases leading to vision loss. The Diabetic Retinopathy Clinical Research Network (DRCRnet), a collaboration of private and academic practices supported by the National Eye Institute and the National Institute of Diabetes, Digestive and Kidney Diseases has studied diabetic eye disease for 13 years. This review will discuss the network's findings over the last year, when some of its most important contributions were reported. RECENT FINDINGS: The DRCRnet reported intravitreal bevacizumab, ranibizumab and aflibercept all improve visual acuity in DME. With baseline vision of 20/30 to 20/40, all agents had similar efficacy. With baseline vision of 20/50 or worse, aflibercept resulted in superior visual improvement. Protocol S, which compared panretinal photocoagulation with intravitreal injections of ranibizumab for proliferative diabetic retinopathy (PDR), found vision outcomes and surgery rates were not inferior in the injection group. Secondary outcomes indicate improved functional results with ranibizumab supporting injections as a possible alternative treatment for PDR. SUMMARY: The DRCRnet has helped clarify the role of various treatments for both DME and PDR, and will continue to evaluate treatments for these vision-threatening conditions.


Asunto(s)
Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/complicaciones , Retinopatía Diabética/terapia , Hemorragia/etiología , Humanos , Coagulación con Láser , Trastornos de la Visión/etiología , Trastornos de la Visión/fisiopatología , Agudeza Visual
9.
Ophthalmology ; 122(2): 375-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25439614

RESUMEN

OBJECTIVE: To report 5-year results from a previously reported trial evaluating intravitreal 0.5 mg ranibizumab with prompt versus deferred (for ≥24 weeks) focal/grid laser treatment for diabetic macular edema (DME). DESIGN: Multicenter, randomized clinical trial. PARTICIPANTS: Among participants from the trial with 3 years of follow-up who subsequently consented to a 2-year extension and survived through 5 years, 124 (97%) and 111 (92%) completed the 5-year visit in the prompt and deferred groups, respectively. METHODS: Random assignment to ranibizumab every 4 weeks until no longer improving (with resumption if worsening) and prompt or deferred (≥24 weeks) focal/grid laser treatment. MAIN OUTCOME MEASURES: Best-corrected visual acuity at the 5-year visit. RESULTS: The mean change in visual acuity letter score from baseline to the 5-year visit was +7.2 letters in the prompt laser group compared with +9.8 letters in the deferred laser group (mean difference, -2.6 letters; 95% confidence interval, -5.5 to +0.4 letters; P = 0.09). At the 5-year visit in the prompt versus deferred laser groups, there was vision loss of ≥10 letters in 9% versus 8%, an improvement of ≥10 letters in 46% versus 58%, and an improvement of ≥15 letters in 27% versus 38% of participants, respectively. From baseline to 5 years, 56% of participants in the deferred group did not receive laser. The median number of injections was 13 versus 17 in the prompt and deferral groups, including 54% and 45% receiving no injections during year 4 and 62% and 52% receiving no injections during year 5, respectively. CONCLUSIONS: Five-year results suggest focal/grid laser treatment at the initiation of intravitreal ranibizumab is no better than deferring laser treatment for ≥24 weeks in eyes with DME involving the central macula with vision impairment. Although more than half of eyes in which laser treatment is deferred may avoid laser for at least 5 years, such eyes may require more injections to achieve these results when following this protocol. Most eyes treated with ranibizumab and either prompt or deferred laser maintain vision gains obtained by the first year through 5 years with little additional treatment after 3 years.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Retinopatía Diabética/terapia , Coagulación con Láser , Edema Macular/terapia , Anciano , Terapia Combinada , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/cirugía , Femenino , Humanos , Inyecciones Intravítreas , Edema Macular/tratamiento farmacológico , Edema Macular/cirugía , Masculino , Persona de Mediana Edad , Ranibizumab , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Agudeza Visual/fisiología
10.
Anal Chem ; 86(2): 1007-15, 2014 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-24377301

RESUMEN

Confocal Raman spectroscopy is a nondestructive analytical technique that combines the chemical information from vibrational spectroscopy with the spatial resolution of confocal microscopy. It was applied, for the first time, to measure protein desorption from chromatographic particles. Monoclonal antibody was loaded onto the Fractogel EMD SO3 (M) cation exchanger at either pH 5 or pH 4. Confocal Raman measurement suggests that only the protein loaded at pH 5 is able to release from chromatographic particles in the elution buffer. Detailed comparison of high-quality spectra indicates that, while proteins loaded at both pH values showed a predominant ß-sheet conformation, protein loaded at pH 4 has a broader amide I band with more intensity in the >1680 cm(-1) region. This small but clear and reproducible amide I bandwidth increase is not observed for protein in the solution state at pH 4. No definitive assignment of the increased Raman intensity in the >1680 cm(-1) region could be made, but it might be related to structural changes involved in the association of protein molecules in the adsorbed state, which helps to explain the nearly 100% retention under elution conditions of the monoclonal antibody adsorbed at pH 4 in chromatographic particles.


Asunto(s)
Anticuerpos Monoclonales/análisis , Resinas de Intercambio Iónico/química , Adsorción , Animales , Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/aislamiento & purificación , Células CHO , Cricetulus , Concentración de Iones de Hidrógeno , Intercambio Iónico , Microscopía Confocal , Estructura Secundaria de Proteína , Soluciones , Espectrometría Raman/métodos , Vibración
11.
Anal Chem ; 84(17): 7367-73, 2012 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-22803776

RESUMEN

Confocal Raman microscopy is a nondestructive analytical technique that combines the chemical information from vibrational spectroscopy with the spatial resolution of confocal microscopy. It was applied, for the first time, to measure conformation and distribution of protein adsorbed in wetted chromatographic particles. Monoclonal antibody was loaded into the Fractogel EMD SO(3) (M) cation exchanger at 2 mS/cm or 10 mS/cm. Amide I and III frequencies in the Raman spectrum of the adsorbed protein suggest that there are no detectable changes of the original ß-sheet conformation in the chromatographic particles. Protein depth profile measurements indicate that, when the conductivity is increased from 2 mS/cm to 10 mS/cm, there is a change in mass transport mechanism for protein adsorption, from the shrinking-core model to the homogeneous-diffusion model. In this study, the use of confocal Raman microscopy to measure protein distribution in chromatographic particles fundamentally agrees with previous confocal laser scanning microscopic investigations, but confocal Raman spectroscopy enjoys additional advantages: use of unlabeled protein to eliminate fluorescent labeling, ability for characterization of protein secondary structure, and ability for spectral normalization to provide a nondestructive experimental approach to correct light attenuation effects caused by refractive index (RI) mismatching in semiopaque chromatographic particles.


Asunto(s)
Anticuerpos Monoclonales/metabolismo , Resinas de Intercambio de Catión/metabolismo , Microscopía Confocal , Adsorción , Anticuerpos Monoclonales/química , Resinas de Intercambio de Catión/química , Unión Proteica , Estructura Secundaria de Proteína , Espectrometría Raman
12.
J Res Natl Inst Stand Technol ; 117: 185-201, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-26900523

RESUMEN

The need to understand and monitor climate change has led to proposed radiometric accuracy requirements for space-based remote sensing instruments that are very stringent and currently outside the capabilities of many Earth orbiting instruments. A major problem is quantifying changes in sensor performance that occur from launch and during the mission. To address this problem on-orbit calibrators and monitors have been developed, but they too can suffer changes from launch and the harsh space environment. One solution is to use the Moon as a calibration reference source. Already the Moon has been used to remove post-launch drift and to cross-calibrate different instruments, but further work is needed to develop a new model with low absolute uncertainties capable of climate-quality absolute calibration of Earth observing instruments on orbit. To this end, we are proposing an Earth-based instrument suite to measure the absolute lunar spectral irradiance to an uncertainty(1) of 0.5 % (k=1) over the spectral range from 320 nm to 2500 nm with a spectral resolution of approximately 0.3 %. Absolute measurements of lunar radiance will also be acquired to facilitate calibration of high spatial resolution sensors. The instruments will be deployed at high elevation astronomical observatories and flown on high-altitude balloons in order to mitigate the effects of the Earth's atmosphere on the lunar observations. Periodic calibrations using instrumentation and techniques available from NIST will ensure traceability to the International System of Units (SI) and low absolute radiometric uncertainties.

13.
Psychol Rep ; 125(4): 2249-2273, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33957821

RESUMEN

A calculative mindset (CM) describes the tendency to analyze and convert qualitative social values into numeric or monetary metrics and is a predisposition that shapes behaviors and actions of the employee. CM has been manipulated in experimental studies, but it has not been investigated in field research due to the absence of a scale to measure CM. In study 1, we followed Hinkin's scale development protocol to conceptualize, develop, and validate a measure of CM to facilirate research in organizational contexts. In Study 2, we examined the relationship between CM and measures of performance, counterproductive work behavior (CWB), organizational citizenship behaviors (OCB), and in role-performance (IRP). Results from hierarchical regression analyses indicate that CM is related to these performance outcomes and explains incremental variance over established measures of the Five-Factor Model of personality. Implications for personality research, selection of human resources, and facilitation of an ethical workplace are discussed.


Asunto(s)
Cultura Organizacional , Lugar de Trabajo , Humanos , Personalidad , Conducta Social , Valores Sociales
14.
Otol Neurotol ; 42(5): 765-773, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33492058

RESUMEN

HYPOTHESIS: The primary goal of this study was to examine how accuracy is affected when we employ a guidance device to assist with the execution of the Epley canalolith repositioning procedure. BACKGROUND: Benign paroxysmal positional vertigo is a common cause of vestibular vertigo. Treatment is noninvasive and generally effective when performed correctly. Deficiencies in clinical application result in unnecessary failures in response for those affected. METHODS: Ten participants were each taken through six iterations of the Epley canalolith repositioning procedure. Iterations were divided evenly between those conducted with and without the use of a guidance device. One clinician performed all 60 procedures. Head movements were recorded using motion capture cameras and strategically placed motion tracking markers. RESULTS: Results showed that the guidance device significantly improved the latter phase maneuver accuracy. Rotation error was significantly reduced for hold3 with-device (M = 20.23°, SD = 12.08°) versus without-device (M = 40.13°, SD = 14.62°, p  =  0.001). Maximal rotation error during rotation4 of the maneuver demonstrated a similar reduction of error with-device (M = 24.44°, SD = 10.43°) versus without-device (M = 41.36°, SD = 12.89°, p  =  0.002). CONCLUSION: A simple visual guidance device can increase the execution accuracy of canalith repositioning procedures. Further research is required to show how such improvements influence treatment efficacy.


Asunto(s)
Postura , Dispositivos de Autoayuda , Vértigo Posicional Paroxístico Benigno/terapia , Humanos , Posicionamiento del Paciente , Modalidades de Fisioterapia , Resultado del Tratamiento
15.
Brain Sci ; 11(4)2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33917497

RESUMEN

BACKGROUND: Motor neglect occurs in patients with chronic pain conditions. Virtual environments (VE) help rehabilitation through biofeedback and improving motivation. AIM: To assess the feasibility of a VE for patients with motor neglect with chronic pain. METHODS: 10 subjects with chronic pain (Fibromyalgia, Sciatica, and Complex Regional Pain Syndrome) underwent a treadmill task three times per week for two weeks. Groups were randomized to receive real-time biofeedback from the VE (intervention) or shown still images (control). Primary outcomes were: (i) distance walked at baseline compared to the final 5 min cycle of week 2; (ii) the Lower Extremity Functional Index (LEFI) questionnaire. A satisfaction questionnaire was used. Follow up was to 24 weeks. RESULTS: Total distance walked was significantly higher in the intervention group (p < 0.05), and 33% (2/6) of the intervention group had a clinically important LEFI improvement compared to 0/4 in the control group at week 2. No secondary outcome measures demonstrated any significant differences. The intervention received high satisfaction scores, significantly greater than the control group at week 24. No harms were recorded. DISCUSSION: This feasibility study showed that VE and treadmill-walking improved walking distances and function for subjects with motor neglect. This is a promising novel approach and requires further validation through larger study.

16.
Front Neurol ; 12: 660383, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34054703

RESUMEN

Background: Walking, sit-to-stand (STS) and sit-to-walk (STW) are all considered important functional tasks in achieving independence after stroke. Despite knowledge that sensitive measurement of movement patterns is crucial to understanding neuromuscular restitution, there is surprisingly little information available about the detailed biomechanical characteristics of, and relationships between, walking, sit-to-stand and sit-to-walk, particularly in the important time window early after stroke. Hence, here, the study aimed to: Identify the biomechanical characteristics of and determine any differences in both movement fluidity (hesitation, coordination and smoothness) and duration of movement phases, between sit-to-stand (STS) and sit-to-walk (STW) in people early after stroke.Determine whether measures of movement fluidity (hesitation, coordination, and smoothness) and movement phases during sit-to-stand (STS) and/or sit-to-walk (STW) are correlated strongly to commonly used measures of walking speed and/or step length ratio in people early after stroke. Methods: This study consisted of secondary data analysis from the SWIFT Cast Trial. Specifically, we investigated movement fluidity using established assessments of smoothness, hesitation and coordination and the time duration for specific movement phases in a group of 48 people after stroke. Comparisons were made between STS and STW and relationships to walking measures were explored. Results: Participants spent significantly more time in the initial movement phase, flexion momentum, during STS [mean time (SD) 1.74 ±1.45 s] than they did during STW [mean time (SD) 1.13 ± 1.03 s]. STS was also completed more smoothly but with more hesitation and greater coordination than the task of STW. No strong relationships were found between movement fluidity or duration with walking speed or step length symmetry. Conclusions: Assessment of movement after stroke requires a range of functional tasks and no one task should predominate over another. Seemingly similar or overlapping tasks such as STS and STW create distinct biomechanical characteristics which can be identified using sensitive, objective measures of fluidity and movement phases but there are no strong relationships between the functional tasks of STS and STW with walking speed or with step-length symmetry.

17.
Sci Total Environ ; 798: 149177, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34375259

RESUMEN

Standardized protocols for wastewater-based surveillance (WBS) for the RNA of SARS-CoV-2, the virus responsible for the current COVID-19 pandemic, are being developed and refined worldwide for early detection of disease outbreaks. We report here on lessons learned from establishing a WBS program for SARS-CoV-2 integrated with a human surveillance program for COVID-19. We have established WBS at three campuses of a university, including student residential dormitories and a hospital that treats COVID-19 patients. Lessons learned from this WBS program address the variability of water quality, new detection technologies, the range of detectable viral loads in wastewater, and the predictive value of integrating environmental and human surveillance data. Data from our WBS program indicated that water quality was statistically different between sewer sampling sites, with more variability observed in wastewater coming from individual buildings compared to clusters of buildings. A new detection technology was developed based upon the use of a novel polymerase called V2G. Detectable levels of SARS-CoV-2 in wastewater varied from 102 to 106 genomic copies (gc) per liter of raw wastewater (L). Integration of environmental and human surveillance data indicate that WBS detection of 100 gc/L of SARS-CoV-2 RNA in wastewater was associated with a positivity rate of 4% as detected by human surveillance in the wastewater catchment area, though confidence intervals were wide (ß ~ 8.99 ∗ ln(100); 95% CI = 0.90-17.08; p < 0.05). Our data also suggest that early detection of COVID-19 surges based on correlations between viral load in wastewater and human disease incidence could benefit by increasing the wastewater sample collection frequency from weekly to daily. Coupling simpler and faster detection technology with more frequent sampling has the potential to improve the predictive potential of using WBS of SARS-CoV-2 for early detection of the onset of COVID-19.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Pandemias , ARN Viral , Aguas Residuales
18.
Clin Ophthalmol ; 14: 557-569, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32161441

RESUMEN

The management of vitreoretinal cases is ever-evolving, paralleled by rapid advancements in operative imaging modalities. In this article, we describe an advanced application of digitally assisted vitreoretinal surgery (DAVS) that involves the consolidation of pre-existing ancillary imaging technology into a single same-screen viewing platform. Forty-four eyes of 44 patients were operated using same screen simultaneous viewing of the primary three-dimensional high definition (3DHD) surgical field and simultaneous auxiliary video feed viewing of all currently approved ocular endoscopy (n=12), intraoperative optical coherence tomography (iOCT) units (n=24), or computer feeds from the EHR/image management software (n=8). All surgeries were successful with excellent functional and anatomic outcomes. DAVS facilitated same screen viewing of multiple video/information feeds was notable for improved ergonomics, surgical efficiency, and precision when compared to viewing the surgical field and auxiliary video feeds separately. We describe a new concept for the vitreoretinal operating room - a DAVS-based surgical information handling cockpit - integrating FDA approved ocular endoscopy (n=1), microscope-integrated iOCT units (n=3), and one EHR/Image management solution with the primary surgical field 3DHD feed. We suggest same screen viewing of multiple video and other clinical information feeds is a promising modality that may be considered in the management of patients with surgical vitreoretinal disease and should be purposefully incorporated into future iterations of DAVS technology platforms.

19.
Lancet Child Adolesc Health ; 4(2): 121-130, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31786093

RESUMEN

BACKGROUND: Marked variation exists in the use of genomic data in tumour diagnosis, and optimal integration with conventional diagnostic technology remains uncertain despite several studies reporting improved diagnostic accuracy, selection for targeted treatments, and stratification for trials. Our aim was to assess the added value of molecular profiling in routine clinical practice and the impact on conventional and experimental treatments. METHODS: This population-based study assessed the diagnostic and clinical use of DNA methylation-based profiling in childhood CNS tumours using two large national cohorts in the UK. In the diagnostic cohort-which included routinely diagnosed CNS tumours between Sept 1, 2016, and Sept 1, 2018-we assessed how the methylation profile altered or refined diagnosis in routine clinical practice and estimated how this would affect standard patient management. For the archival cohort of diagnostically difficult cases, we established how many cases could be solved using modern standard pathology, how many could only be solved using the methylation profile, and how many remained unsolvable. FINDINGS: Of 484 patients younger than 20 years with CNS tumours, 306 had DNA methylation arrays requested by the neuropathologist and were included in the diagnostic cohort. Molecular profiling added a unique contribution to clinical diagnosis in 107 (35%; 95% CI 30-40) of 306 cases in routine diagnostic practice-providing additional molecular subtyping data in 99 cases, amended the final diagnosis in five cases, and making potentially significant predictions in three cases. We estimated that it could change conventional management in 11 (4%; 95% CI 2-6) of 306 patients. Among 195 historically difficult-to-diagnose tumours in the archival cohort, 99 (51%) could be diagnosed using standard methods, with the addition of methylation profiling solving a further 34 (17%) cases. The remaining 62 (32%) cases were unresolved despite specialist pathology and methylation profiling. INTERPRETATION: Together, these data provide estimates of the impact that could be expected from routine implementation of genomic profiling into clinical practice, and indicate limitations where additional techniques will be required. We conclude that DNA methylation arrays are a useful diagnostic adjunct for childhood CNS tumours. FUNDING: The Brain Tumour Charity, Children with Cancer UK, Great Ormond Street Hospital Children's Charity, Olivia Hodson Cancer Fund, Cancer Research UK, and the National Institute of Health Research.


Asunto(s)
Neoplasias del Sistema Nervioso Central/diagnóstico , Metilación de ADN/fisiología , Regulación Neoplásica de la Expresión Génica/fisiología , Terapia Molecular Dirigida , Biomarcadores de Tumor/genética , Neoplasias del Sistema Nervioso Central/genética , Neoplasias del Sistema Nervioso Central/terapia , Niño , Humanos , Estudios Retrospectivos , Telomerasa
20.
Front Psychol ; 10: 690, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31024377

RESUMEN

Insects use path integration (PI) to maintain a home vector, but can also store and recall vector-memories that take them from home to a food location, and even allow them to take novel shortcuts between food locations. The neural circuit of the Central Complex (a brain area that receives compass and optic flow information) forms a plausible substrate for these behaviors. A recent model, grounded in neurophysiological and neuroanatomical data, can account for PI during outbound exploratory routes and the control of steering to return home. Here, we show that minor, hypothetical but neurally plausible, extensions of this model can additionally explain how insects could store and recall PI vectors to follow food-ward paths, take shortcuts, search at the feeder and re-calibrate their vector-memories with experience. In addition, a simple assumption about how one of multiple vector-memories might be chosen at any point in time can produce the development and maintenance of efficient routes between multiple locations, as observed in bees. The central complex circuitry is therefore well-suited to allow for a rich vector-based navigational repertoire.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA